The fourth chapter of my running, preliminary commentary on Romans may be found here: 

These are some key points from Romans 4 that I discuss in my commentary:

1. How was Abraham justified (made whole in his relationship with God)?  God’s gifting call came first, then Abraham’s trust, and then, in response, Abraham’s following the commands (i.e., circumcision, the classic boundary-marking command).

2. To one who trusts in following the commands as the way of gaining God’s favor, the favor God bestows (“wages”) are “something due,” not a “gift” (4:4).  In contrast, to one who recognizes that God’s favor is from the start a gift that need not be earned, trust in God is what counts as the basis for their being seen as just.

3. In Genesis, Abraham was called in chapter 12 and not circumcised until chapter 17.  The circumcision was a “sign” that served as a “seal of the justice he had by faith” (4:11).  The justice, though, was established before Abraham’s circumcision.  

4. When Paul speaks of God’s promise that Abraham and his descendants “would inherit the world” (4:13), he may have in mind the promise of Genesis 12:3 that Abraham’s descendents would “bless all the families of the earth.”  Paul’s own apostleship to the Gentiles (1:5) may be seen as his acting on the confidence that he is part of the embodiment of the “inheritance” promised Abraham.

5. “The law brings wrath” (4:15) means: “Trusting in the law as an idol separated from God’s motivating mercy brings with it negative consequences.  Those so trusting lose touch with this mercy and instead are possessed by the rules in ways that lead to violence and injustice.”

6. Paul is not meaning to imply that Israel is no longer part of God’s covenant.  He merely argues, based on the original scope of the promise to Abraham and Sarah, that this promise includes both “adherents  of the law” and those “outside the law,” that is, both Jews and Gentiles.

7. In the beginning of Israel, God brought into being something new, out of nothing, an act of pure mercy.  If God did such a work in the time of Abraham, there is no reason why God could not do it again.  The Gentiles who trust in God in Paul’s context are not less worthy of God’s mercy (and no less uncircumcised) than Abraham had been when God first called him.

8. Paul’s punch line: “the words ‘it was reckoned to him,’ were written not for [Abraham’s] sake alone, but for ours also” (4:23-24).  This story Abraham is a present reality throughout all of history, showing how God works with human beings and providing a model for human responsiveness to God.